There are two reasons this might be happening:
- In order to use this NTSC hardware, you MUST connect a display capable of driving 640 x 480 at 60 Hz. You will have to connect an Apple or 3rd party multiple scan display to get this resolution and use the NTSC video-out solution. NOTE: Several Apple displays (13 inch, 14 inch, Performa, Performa Plus and 16 inch) do not support 640 x 480 at 60 Hz, and will not work properly with the NTSC video-out hardware. Apple has had reports of no video, or unreadable video with fixed resolution displays.
- The display MUST be connected to the CPU at the time the CPU is started. You cannot solely connect an NTSC monitor and expect to see something on the TV. You will not see anything on the NTSC monitor unless a display is connected to the 6500 before it starts up.
This article was published in the 29 May 1997 "Information Alley".